Human Menopausal Gonadotropins are protein hormones secreted by gonadotrope cells of the pituitary gland of vertebrates.

Gonadotropin is sometimes abbreviated Gn. The British spelling isgonadotrophin.

TYPES

The two principal gonadotropins are luteinizing hormone (LH) and follicle stimulating hormone (FSH). Both hormones consist of two peptide chains, an alpha chain and a beta chain, linked by Hydrogen bonds and van der Waals forces. LH and FSH share nearly identical alpha chains, while the beta chain provides specificity for receptor interactions.

A third human gonadotropin is human chorionic gonadotropin (hCG), produced by the placenta during pregnancy.

MECHANISM

Gonadotropin receptors are embedded in the surface of the target cell membranes and coupled to the G-protein system. Signals triggered by binding to the receptor are relayed within the cells by the cyclic AMP second messenger system.

Gonadotropins are released under the control of gonadotropin-releasing hormone (GnRH) from the arcuate nucleus and preoptic area of the hypothalamus. The gonads - testes and ovaries - are the primary target organs for LH and FSH. The gonadotropins affect multiple cell types and elicit multiple responses from the target organs. As a simplified generalization, LH stimulates the Leydig cells of the testes and the theca cells of the ovaries to produce testosterone (and indirectly estradiol), while FSH stimulates the spermatogenic tissue of the testes and the granulosa cells of ovarian follicles.

DISEASES

Gonadotropin deficiency due to pituitary disease results in hypogonadism, which can lead to infertility. Treatment include administered gonadotropins, which therefore work as fertility medication. Such can either be produced by extraction and purification from urine or it can be produced by recombinant DNA.

Failure or loss of the gonads usually results in elevated levels of LH and FSH in the blood.

MANNY RAMIREZ CONTROVERSY

Major League Baseball player Manny Ramirez was suspended for 50 games on May 6, 2009, for allegedly failing a drug test which identified gonadotropin.

DESCRIPTION :

hMG is produced from a sterile preparation of placental glucoprotein urine of post-menopausal women. The hMG is purified by proprietary chromatographic techniques.

Lyophilized from a concentrated (1 mg/ml) solution in water containing no additives.

SOLUBILITY:

It is recommended to reconstitute the lyophilized hMG in sterile 18MO-cm H2O not less than 100 g/ml, which can then be further diluted to other aqueous solutions.

STABILITY:

Lyophilized hMG although stable at room temperature for 3 weeks, should be stored desiccated below -18 C. Upon reconstitution hMG should be stored at 4 C between 2-7 days and for future use below -18 C. For long term storage it is recommended to add a carrier protein (0.1% HSA or BSA). Please avoid freeze-thaw cycles.

Protein quantitation was carried out by two independent methods: 1. UV spectroscopy at 280 nm . 2. Analysis by RP-HPLC, using a standard solution of hMG as a Reference Standard.

STORAGE :

should be stored desiccated below -18°C. Upon reconstitution HMG should be stored at 4°C between 2-7 days and for future use below -18°C. For long term storage it is recommended to add a carrier protein (0.1% HSA or BSA). Please avoid freeze-thaw cycle.